LED Headlight Issue

[Price Terzis]

There is an article on how to rewire already - not sure if it solves the issues of providing a path to ground for low and switching low off when high comes on: https://www.bmw2002faq.com/articles/technical-articles/electrical-and-ignition/headlight-and-fogdriving-light-wiring-upgrades-r340/

 

[bpeckm]

Quite new to the auto end of BMW's, I've had 60's-era BMW motorcycles, and with One Eye Only, the headlight was critical.  We debated to/fro about LED's vs halogens, color vs. focus etc.   On the bikes, the lenses were set up for a single-point light-source, and worked well, whereas installing just an LED bulb, they tend to have lotsa little lightpoints spread over 1/2" or so, causing the stock reflectors to not work so well.  A huge issue with the classic bikes was their ability to produce the wattage for the 70/100w halogens, so the LED's were intriguing.  I guess for me it comes down to "light on the road", and a good H4 is still what I want... ymmv as they say!

[HobieDog]

Any updated here @OldRoller?  I’m curious what you think of the lights and if you can share any more about their performance.  I’m considering going down this road. 

[OldRoller]

4 hours ago, Price Terzis said:

There is an article on how to rewire already

Yes, that article addresses adding a high beam relay to single relay (early) 02's, as well as driving lights and other stuff.

The issue I had was with the late model (74-76, maybe 73) cars with two relays for the head lights. This issue only raises its head when using LED headlamps, as stated in the original post.

The change required a 5 pin relay to switch the ground for the low beam relay off when high beams are selected, triggered by the high beam relay request wire. Simple enough, now the circuits are independent and the led headlights work as designed.

[OldRoller]

4 minutes ago, HobieDog said:

 I’m curious what you think of the lights

I have yet to drive the car at night, so my first hand road experience is zero. But in the shop with doors closed and lights off, the beams are a whiter light than H4's. On low beam the spread is low left and rises to the right. High beams are up and centered. The beam spread is reminiscent of my old SEV Marshal flat lens the I had in the Healey, but brighter whiter light.

The halos (or 'angel eyes') are bright cotton white, and coupled with the yellow turn signal switchback feature greatly increases the visibility of our little rockets to other road-sharing drivers.

Would I spend the hundreds for these lights on my 74? I'll have to spend some time in the dark with them before I throw the H4s in the neighbor's lake.  But they are what my friend wanted and I built the car for him. He's dragging me screaming into the electronic world....

I will post more impressions as they come. 

[Sparkles]

I know y'all weren't asking me, but I threw some LED units in my '75 a few weeks ago to replace some seriously dim lights. They turned out to be crusty old H4 adapter sets, one with a boot that had been missing for quite a while and due to the resultant rust on the reflector was making about enough light to read a map by, so not nearly enough to drive on. Being a night owl do a lot of driving after dark, and they've both been working great since with minimal adjustment and no wiring issues like OldRoller had. Mine also have halo rings like OldRoller's, but I haven't had the time (or weather) to wire them in yet, so they're currently inactive, much to my annoyance. I'll get pictures when I have that done. I'm disabled and tend to have really low energy, so it may be a bit.

[xavier296]

This thread was so helpful! I have Dapper Lighting OE7s in my car, with LED bulbs, and they have always worked incorrectly due to the issues described above with the ground going through the high beam (HB) filament. 

 

I fixed it in a slightly different way than OldRoller:

 

First, remove Low beam(LB) relay 85 terminal. Using a female terminal made to go in a relay holder, make a length of wire and with a loop on the other end and ground it to the ground bolt next to the relays

Second, remove LB 86 terminal

Remove ALL terminals from HB relay and put the wires in to a 5 terminal relay base in the same spots. Add a jumper at the HB 87a spot and run the wire to the LB 86 terminal. Make sure the 5 terminal relay you install has an 87a connection and not a redundant 87 terminal (where they both are connected to 30 when the relay is energized).

Cover/tape all unused terminals that have not been reinstalled. 

 

This rewire will ensure the correct function of the high and low beams with LEDs and only provides power to one or the other. Actually, your normal halogens would also work with this setup if you needed to put them back in. 

 

I had some cheap amazon 5 terminal relay/relay holders, and they are sized such that you can tuck the 5 terminal relay in to the same spot the old HB relay was. Everything could also be reinstalled to stock easily since no wires were cut.

[xavier296]

On 2/18/2024 at 9:07 PM, Sparkles said:

I know y'all weren't asking me, but I threw some LED units in my '75 a few weeks ago to replace some seriously dim lights. They turned out to be crusty old H4 adapter sets, one with a boot that had been missing for quite a while and due to the resultant rust on the reflector was making about enough light to read a map by, so not nearly enough to drive on. Being a night owl do a lot of driving after dark, and they've both been working great since with minimal adjustment and no wiring issues like OldRoller had. 

 

So I thought mine were working correctly for a good while, but it turned out that they were either HB or LB + voltage at HB, which means you are technically always driving with your HBs on. The LEDs don't need a lot of voltage to illuminate, so the ground wire actually energizes the HB somewhat. Either one of our fixes would ensure you actually have fully separate circuits and not driving around with your HBs on.

[Sparkles]

On 2/27/2024 at 6:35 AM, xavier296 said:

 

So I thought mine were working correctly for a good while, but it turned out that they were either HB or LB + voltage at HB, which means you are technically always driving with your HBs on. The LEDs don't need a lot of voltage to illuminate, so the ground wire actually energizes the HB somewhat. Either one of our fixes would ensure you actually have fully separate circuits and not driving around with your HBs on.

Thanks for the warning and I'll make sure to double-check the high side with my multimeter when I'm running the wiring for the extra features on the new headlights. But as my horn isn't working at the moment (haven't had time to take the E21 wheel she came with off and make the adjustments I've read about elsewhere in the forums) and I'm making very.... creative use of the high beam dipper switch on the left stalk to compensate (as best I can, at any rate), you could say I check that very regularly. Chicago drivers are rather awful. Also, my garage door is manual, so pull out, close, walk back while gazing at that pretty front end. No glow in the highs (and I tend to drive with my lights on out of habit), but again, I'll check it to make sure and report back.

The wiring makes the Italian part of my heritage shudder every time I look at how hacked up some of it is, so I'm not making assumptions in either direction without actually checking.

Edited February 28 by Sparkles
errant adverb

[Sparkles]

I'm baaaaaack! I did say it'd take a while, yeah?

Well I finally got far enough down my to-do lists that I had started to prep to do one of the recommended mods - since there was a little quirk with the right light's halo rings both working at once when I had the turn signal on regardless of how I wired it - so I figured she was still stock there.... and then on the way back inside after cleaning the bejeebers out of the relay connections, I noticed that some of the former homeowner's bodged repairs are coming back to haunt me after a wind storm. How I missed that the first two times I walked by, I don't know, but holes in the roof take priority, so I put everything back together as it was, but cleaner, and now the low beams don't work unless I ask them very nicely and stop when I flip the high beams on, and now the highs glow like everyone else mentioned. On the plus side, she's been lowered (not sure I'll keep that) so no one seems to notice if I'm just running on the high beams or not! 😆I'll fix it soon, but priorities.

As an additional, relevant note, I can confirm that these LED bulbs will work with the stock turn signal relay! Because the cheap one I'd bought went kaput, and I just threw the original in to troubleshoot, expecting them to stay on. Bugger worked! I'd initially just chalked it up to more grounding issues, but was just doing my due diligence on the chance I was wrong in my assumption.